Stress Relief
Thermal and moisture treatment relieves the internal stresses locked into yarns during weaving or spinning. This process, termed hydrothermal fabric relaxation, achieves dimensional stability by allowing fibers to return to their equilibrium state. It involves exposing the fabric to steam or hot water in a controlled tensionless environment.
Relaxation Mechanism
Heat and water act as plasticizing agents that break the temporary intermolecular bonds in the fiber polymer. During hydrothermal fabric relaxation, the yarn crimp adjusts and the structure contracts.
Finishing Treatment
Industrial finishing lines use continuous steaming tunnels or open-width washing machines to treat tensionless fabric. Incorporating hydrothermal fabric relaxation at this stage prevents distortions in the final garment. The treated fabric exhibits a fuller handle and more uniform appearance.
This process also ensures that the fabric responds consistently to subsequent dyeing. Uniform relaxation prevents the formation of color streaks and uneven finishes.
Dimensional Stability
Garment manufacturers require fabrics that will not change size when laundered by the consumer. Testing laboratories evaluate the effectiveness of hydrothermal fabric relaxation by measuring the length and width of fabric before and after steaming. Stable fabrics reduce the risk of garment rejection after cutting.
They provide the consistency needed for high-volume apparel manufacturing.
